The bridge control system did not perform as it was supposed to. It was reported that the manoeuvring orders were carried out normally and promptly by the bridge personnel.Findings The bridge control system did not perform as it was supposed to. It was reported that the manoeuvring orders were carried out normally and promptly by the bridge personnel. The Transportation Safety Board of Canada determined that the FEDERAL MACKENZIE struck ship arrester No. 2 in the St. Lambert Lock because of an electronic failure in the bridge control system that limited the percentage pitch of the propeller and the engine rpm to 28 per cent of capacity.Causes and Contributing Factors The Transportation Safety Board of Canada determined that the FEDERAL MACKENZIE struck ship arrester No. 2 in the St. Lambert Lock because of an electronic failure in the bridge control system that limited the percentage pitch of the propeller and the engine rpm to 28 per cent of capacity.